The present invention is related to test fixtures, and particularly to test fixtures for testing optical devices such as laser diodes.
To ensure high quality and high yield circuits, circuit components, such as optical devices (e.g., laser diodes and wavelength division multiplexers), are tested prior to bonding the devices to the circuit. For optical devices, this testing typically comprises measuring front light, rear light, and spectral performance of each device.
Previous test fixtures for performing these tests align and handle each device individually. The time required to align and handle each individual device often exceeds the actual time to test the device. Test fixtures typically move devices from one test station to another using stepper motors and transfer arms. Often the resolution of the stepper motors and the transfer arms is not sufficient to accurately align the device with the test equipment. Also, stepper motors and transfer arms often do not provide rotational alignment. Further, each stepper motors typically requires a large surface area. Thus, a need exists for a test fixture which is not required to handle each device individually and provides better positional resolution and rotational alignment, while utilizing a smaller surface area.
A test fixture for testing circuit components includes at least one test bar, at least one tray, a test pedestal, a transportable test stage, a pickup collet, a first camera, and a second camera. Each test bar is adapted to contain a plurality of circuit components. Each tray is adapted to contain a plurality of test bars. The test pedestal is adapted to hold at least one test bar. The transportable test stage includes at least one tray and the test pedestal. The tray(s) and test pedestal are in a fixed position with respect to the test stage. The pickup collet picks up and places the test bar(s). The first camera is used to visually align the pickup collet, and the second camera is used to visually align the test bar(s) with a test site.